Visual information is very important to generate intelligent behavior. For human, about 70% of the information received are visual. Computer vision technology may enable a machine to acquire visual information through camera, just like human eyes. With the visual information, a machine may perform human-like intelligent action by sensing the environment, which potentially has many applications. Despite of the great potential, vision based sensor is not widely used in small interactive devices, such as electronic toys. Some common reasons are: a. Processing visual information usually requires large amount of computation resources, such as large internal memory, high processor speed. b. These large amount of computational resources will consume a significant amount of energy. These two factors will significantly increase the manufacture and operating cost of the small interactive devices such as toys.